Large Scale Management - Linux vs Solaris?

A not-so anonymous, Anonymous Coward asks: "I work for a college that offers undergraduate computer science classes, and the school would like to add a new lab with about a hundred computers for students to use, for various class projects. After some non-trivial effort, we convinced the school to set up a Unix lab rather than a Windows one. However, we can't decide whether to go for Solaris or Linux. Regardless of the cost of hardware, I couldn't get agreed with my colleagues about the amount of efforts required to manage a hundred of Linux PCs vs. a hundred Sparc boxes. I believe that there are many Slashdot readers are actual managers for labs like this if not in large scales. What are your experiences of managing Linux PCs versus traditional Solaris boxes?"

"My detailed questions are:

1. Compared between these two different systems, how easy to maintain the software for all these machines (including re-installation, patching, and updating)? What software do you use to make these management jobs easier?

2. Are there any fundamental differences between managing a large group of linux PCs and managing a large group of Solaris boxes?"